This is one of those, "I'm not sure which community this belongs in".
When configuring Mobile Email Access option (Admin Center-->Settings-->Services & add-ins-->Mobile email access options) to restrict to "Outlook only" as follows, mobile clients still are able to use email apps other than Outlook to access mail. It's as if this setting is being completely ignored. We do have EMS/Intune licenses on this tenant, but they are currently not being used for mobile devices.
Does anyone here have experience with this setting?
I don't even see that option, not in my O365 tenant, not in the M365 one. I imagine it's something new, but since I cannot play with it, I cannot tell you what exactly it does. It might be setting an Intune policy, or it might simply be configuring a list of allowed apps via the Exchange controls. Where does the help link take you to?
@Vasil Michev I don't think it's that new - the docs page for it is dated 11/2018. The availability of the feature depends on whether you're using Intune or MDM from the EAC. We use neither, which is why we have the feature lit up for us.